Scaling relations for brittle fracture of entangled polystyrene melts and solutions in elongational flow

The criterion for brittle fracture of entangled polymer liquids [Wagner et al., J. Rheol. 62, 221–223 (2018)] is extended by including the effects finite chain extensibility and concentration. Crack initiation follows from rupture primary C–C bonds, when strain energy entanglement segments reaches covalent bond. Thermal fluctuations will concentrate on one bond segments, leading to scission chains followed crack fast growth. In start-up flows, characterized long relaxation times, i.e., predominantly those in middle chain, be first reach critical fracture. Recent experimental data Huang [Phys. Fluids 31, 083105 (2019)] a monodisperse polystyrene melt several solutions polystyrenes dissolved oligomeric styrene are agreement with scaling relations Weissenberg number as well Hencky stress at derived this interchain pressure model [Narimissa, Huang, Wagner, 64, 95–110 (2020)].